(LEAD) S. Korea vows pre-emptive responses over Brexit unrest: PM
(ATTN: UPDATES with prime minister's speech in first 7 paras; CHANGES headline)
By Kim Deok-hyun
TIANJIN, China, June 27 (Yonhap) -- Prime Minister Hwang Kyo-ahn said Monday South Korea will take pre-emptive measures to contain market volatility and